The need for DNA sequence data has grown dramatically over the last 5 years with most of the increase related to the role of DNA damage, repair, and environmental mutagens in the development of cancer. The DNA Sequencing shared resource is a centralized core to fulfill the demands for DNA sequencing for many molecular and genetic studies. The facility occupies 300 square feet of space and is located in Rosenkranz #2. The DNA Sequencing shared resource provides high-quality sequencing and genetic analysis services to investigators at the City of Hope Cancer Center. Our goal is to work with each investigator to provide the best type of analysis that is required to maximize research output with turnaround times of 24-48 hrs. The sequencing facility provides software for primer design, sequence editing, sequence analysis, and genetic fragment analysis. Fluorescent DNA sequencing is accomplished using a variety of sequencing chemistries and primers on PCR fragments, DNA plasmids, P1 clones, lambda clones and BAC clones. Methylation of CpG residues has been analyzed. Quantitative fragment analysis using fluorescent primers and RT-PCR is performed. Troubleshooting difficult sequences is accomplished using a variety of chemical agents and sequencing,chemistries. Data is transferred to investigators by email and/or diskettes in formats of the investigator s choice. Printouts of data are also given to each investigator. Archival data is stored on CDs. The sequencing facility was updated with an ABI 377 DNA sequencer with 96-sample capacity, a new thermalcycler, and an 877 Catalyst robotic workstation. A second 377 ABI DNA sequencer was acquired to handle a larger number of samples. Ninety-six-well microtiter plate sequencing techniques were developed for higher efficiency and faster turnaround times. Techniques using the robotic workstation for sequencing and fragment analyses have been implemented. A computer workstation was made available for primer design and fragment analyses. A web software program was purchased to handle sample input, data transfer and monthly billing. Peer-reviewed usage of this core by Cancer Center members is 73% of the total samples.